JP4660415B2 - Paper feeding device and document feeding device using the same - Google Patents

Description

  The present invention relates to a paper feeding device that feeds sheets along a conveyance guide or sequentially feeds sheets on a stacker, and relates to a document sheet feeding mechanism in a document feeding device such as a copying machine or a scanner device.

  In general, this type of paper feeding apparatus is a sheet feeding mechanism that sequentially feeds sheets stored in a stacker, or a feeder mechanism that sequentially feeds sheets prepared in a sheet guide downstream, such as an image forming apparatus such as a copying machine, a scanner apparatus, etc. Used for a wide range of equipment. The mechanism feeds sheets prepared in a conveyance guide, a paper feed stacker, and the like to a downstream side by a frictional force by a rotating body (hereinafter referred to as roller means) such as a roller and a belt. A mechanism for raising and lowering the roller means to a position where it comes into contact with the sheet and a position where it is retracted according to the sheet feeding timing when the sheet is fed downstream is also widely used.

For example, Patent Document 1 discloses a mechanism for feeding roller means (kick rollers) on a stacker to a downstream paper feed roller when sheets stacked from a paper feed stacker are sequentially fed downstream. In this document, a kick roller is axially supported by an arm-shaped lifting arm member, and a paper feed roller is axially supported at a base end portion thereof. A drive motor is connected to the shaft of the paper feed roller (drive rotation shaft), and the paper feed roller and the kick roller are rotated by the same drive. At the same time, the drive motor is composed of a motor that can be rotated forward and backward in order to raise and lower the kick roller with this drive source, and the drive rotary shaft and the above-mentioned lift arm member base end portion are connected by a spring clutch, and the lift arm member is rotated by rotating the motor. Is swung in the direction in which the kick roller is raised, and is swung in the direction in which the kick roller is lowered by normal rotation. The sheet feeding roller and the kick roller are rotated only in the direction in which the sheet is fed out by the one-way clutch. Further, in the publication, the registration roller located on the downstream side of the paper feed roller is rotated by the reverse rotation of the drive motor. As a result, it is possible to feed, separate and align and feed sheets on the stacker by forward / reverse control of one drive motor, and the drive system is simple and the control is easy.
JP 2002-182437 A

  As described above, for example, when the sheet on the stacker is fed out and separated and fed, the lifting arm member bearing the feeding roller to the drive rotation shaft of the paper feeding roller is connected via the spring clutch. There's a problem. While the driving mechanism is simplified, every time the sheet is fed out, the feeding roller repeatedly moves up and down. This is because the feeding roller lifts up the stacking roller at the same time as the drive motor rotates in reverse, so that the feeding roller inevitably moves up and down between the operating position engaged with the sheet and the retracted position retracted. .

  In this way, every time the sheet is fed out, there arises a problem that a fluttering noise is generated when the feeding roller falls on the sheet from the retracted position. At the same time, there is a problem that when the roller comes into contact with the sheet, the roller partially hits one side to cause wrinkles or skew. In particular, in the image reading apparatus, image blur may occur in the reading unit on the leading end side of the sheet due to vibration when the feeding roller comes into contact with the sheet, and similarly causes image blur due to load fluctuation when the roller moves away from the sheet. Yes. For example, this has a great influence when reading color images and high-definition images. On the other hand, in order to solve such a cause, an attempt has been made to perform the vertical movement of the feeding roller by an independent motor or an electromagnetic solenoid. However, this increases the size and cost of the apparatus.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a paper feeding device that has a simple structure and can easily control a driving mechanism that raises and lowers roller means for feeding a sheet from a stacker or the like between an operating position and a retracted position. Another object of the present invention is to provide a document feeding apparatus that reduces vibration, noise, skew, and the like during sheet feeding when a sheet is separated and fed from a sheet feeding stacker to a predetermined reading position.

  In the present invention, the “friction transmission means” means that a friction engagement surface is formed between the drive-side rotation shaft and the passive-side rotation shaft, and the drive force on the drive rotation side is driven in a predetermined direction or a predetermined range. This means means for transmitting (rotational torque) to the passive-side rotating shaft. “Feeding roller means” means means for conveying a sheet or the like by a frictional force with a rotating body such as a roller or an endless belt.

  The present invention employs the following means in order to solve the aforementioned problems. A placement guide for supporting the sheet; a feeding roller means for feeding the sheet on the placement guide to the downstream side; an operating position for engaging the feeding roller means with the sheet on the placement guide; And an elevating arm member that is swingably supported between the retracted positions separated from each other and a driving unit that rotationally drives the feeding roller unit. A drive rotation shaft having a drive gear connected to the drive means and an intermediate rotation shaft having an intermediate gear arranged at a distance from the drive rotation shaft are provided. The lift arm member and the feeding roller means are connected to the drive rotating shaft and the intermediate rotating shaft as follows.

  First, the first and second transmission gears are swingably attached to the drive rotation shaft so as to roll on the outer periphery of the drive gear. The lifting / lowering arm member is pivotally supported on the intermediate rotating shaft via a friction transmission means, and the feeding roller means is driven and transmitted from the intermediate gear by the transmission means. The first transmission gear meshes with the intermediate gear by one-way rotation of the drive rotation shaft to swing and rotate the lifting arm member in a predetermined direction, and the second rotation by reverse rotation of the drive rotation shaft. The transmission gear is engaged with the intermediate gear so as to swing and rotate the lifting arm member in the opposite direction. As a result, when the driving means is rotated in a predetermined direction, the feeding roller means is driven to rotate simultaneously with the movement from the retracted position to the operating position. Further, the feeding roller means can be moved from the operating position to the retracted position by the reverse rotation of the driving means.

  In this case, the first and second transmission gears are provided with, for example, a rotary arm member on the drive rotary shaft and attached to the rotary arm member. The rotating arm member is provided with shift means for driving and controlling it. Therefore, the shift means is composed of a spring clutch or other friction transmission means arranged between the drive rotary shaft and the rotating arm member, so that the first and second transmission gears can be changed to the intermediate gear by forward and reverse rotation of the drive rotary shaft. The feeding roller means can be lifted and lowered with an inexpensive and simple structure without using a special driving device. The shift means further includes a restriction means for restricting the movement of the rotating arm member in a non-transmission state in which the first and second transmission gears are not meshed with the intermediate gear, and the restriction means is downstream of the feeding roller means. For example, it is linked to the drive motor of the reading roller on the side.

  Next, a document feeding apparatus according to the present invention includes a sheet feeding stacker for placing document sheets, feeding roller means for sequentially feeding document sheets from the sheet feeding stacker, and the feeding roller means as a document on the sheet feeding stacker. A lifting arm member swingably supported between an operating position for engaging with the sheet and a retracted position separated from the original sheet; a paper supply roller for separating and feeding the original sheets from the feeding roller one by one; A registration roller that takes over and conveys the original sheet from the paper feed roller, a reading platen disposed downstream of the registration roller, and is disposed between the registration roller and the reading platen. And a reading roller for feeding the sheet.

  A driving rotary shaft having driving means; a driving gear attached to the driving rotary shaft; an intermediate rotating shaft having an intermediate gear arranged at a distance from the driving rotary shaft; and the driving gear on the driving rotary shaft A first and second transmission gears swingably mounted so as to roll on the outer periphery thereof, and the lift arm member is pivotably supported on the intermediate rotation shaft via a friction transmission means, The feeding roller means is driven and transmitted by the transmission means from the intermediate gear, and the first transmission gear meshes with the intermediate gear by one-way rotation of the drive rotation shaft, and the lifting arm member swings in a predetermined direction. The second transmission gear is engaged with the intermediate gear by the reverse rotation of the drive rotation shaft, and the lifting arm member is configured to swing and rotate in the opposite direction.

  In the present invention, when a sheet on a loading guide such as a stacker is fed downstream by a feeding roller means, a lifting arm member supporting the feeding roller means is pivoted to an intermediate rotation shaft via a friction transmission means. The intermediate gear of the intermediate rotation shaft is supported and driven by the first and second transmission gears swingably disposed on the drive rotation shaft, and the transmission meshes with the intermediate gear by forward and reverse rotation of the drive rotation shaft. Since the gears are switched, the following effects are obtained.

  First, the roller means can be position-controlled between the retracted position and the operating position simultaneously with the rotational driving of the feeding roller means by moving the lifting arm member up and down by forward / reverse rotation of the drive rotating shaft. In this control, when the first and second transmission gears of the drive rotary shaft are switched to the intermediate gears of the lifting arm member, the non-transmission state is provided to engage the feeding roller means with the sheet. Therefore, it is not necessary to raise and lower the feeding roller means each time the sheet is fed, and noise and vibration when the roller contacts the sheet can be reduced. At the same time, there is no risk that the roller will come into contact with the sheet and cause skew. In particular, when reading an image of a document or the like, the feeding roller means on the rear end side does not move to the retracted position during reading on the front end side of the sheet, and image blurring does not occur due to load fluctuations during sheet reading.

  Hereinafter, the present invention will be described in detail based on the preferred embodiments shown in the drawings. FIG. 1 is an explanatory view showing the overall configuration of a document feeding apparatus incorporating a paper feeding apparatus according to the present invention, and FIG. 2 is an explanatory view of the main part thereof.

  A document feeder A shown in FIG. 1 includes a paper feed stacker 10, a paper discharge stacker 31, a U-shaped transport path 40 that transports a document sheet from the paper feed stacker 10 to the paper discharge stacker 31, and a path in the transport path. The document sheet on the paper feed stacker 10 is sequentially conveyed to the paper discharge stacker 31 through the reading platen 30. This document feeder A is mounted on a normal scanner device B, feeds a document sheet on the paper feed stacker 10 to a reading platen 30 on the scanner device side, and discharges a document sheet read by the reading platen 30. It is stored in the stacker 31. Therefore, in the scanner device B, a platen (first platen) 51 on which a document sheet is placed, a carriage 52 that can reciprocate along the platen 51, and a photoelectric conversion unit 53 are arranged in a casing 50. The carriage 52 includes a light source 54 and an optical element 55 such as a mirror, and guides reflected light from the original on the platen to the photoelectric conversion unit 53. The photoelectric conversion unit 53 incorporates a condensing lens 56 and forms an original image on a photoelectric conversion element such as a CCD. A second platen 30 is provided separately from the first platen 51, and the conveyance path 40 is disposed in the second platen 30, so that document sheets are sequentially fed from the paper feed stacker 10 to the second platen 30. It has become.

  A feeding roller unit 11 disposed above the sheet feeding stacker 10, a sheet feeding roller 12 (sheet feeding rotating unit; the same applies hereinafter) for separating and feeding original sheets from the feeding roller unit 11 one by one, A registration roller 13 that takes over and conveys the original sheet from the paper supply roller 12 downstream is sequentially arranged toward the reading platen (second platen) 30 and is drivably coupled to the paper supply motor M1 (first drive motor). ing. A reading roller 41 (carry-in roller; the same applies to the following) is disposed upstream of the reading platen (second platen) 30 and a discharge roller 42 is disposed on the downstream side. A paper discharge stacker 31 downstream of the discharge roller 42 is disposed. The paper discharge rollers 43 are arranged on the front and are connected to the transport motor M2 (second drive motor). A path switching guide 44 and a circulation path 45 are provided downstream of the carry-out roller 42, and the circulation path 45 switches back the document sheet carried to the paper discharge roller 43 and guides it to the registration roller 13. This is because the document sheet from which the front image has been read is reversed and fed again to the reading platen 30 (second platen), and the back image is read. The path switching guide 44 is connected to an electromagnetic solenoid (not shown) different from the drive motors M1 and M2.

  The feeding roller means 11, the feeding roller 12, and the registration roller 13 for transporting the sheet in each of the paths are fed to the feeding motor M1 (first driving motor), the carry-in roller 41, the carry-out roller 42, and the paper discharge roller. Reference numeral 43 is connected to the transport motor M2 (second drive motor) as follows, and each of the drive motors M1 and M2 is constituted by a forward / reverse motor.

  First, the feeding roller means 11 engages with a sheet on the sheet feed stacker 10 and feeds it out (a state shown by a dotted line in FIG. 2) and a retracted position (a state shown by a solid line in FIG. 2) retracted from this position. The lift arm member 14 is movably supported. The elevating arm member 14 has a base end portion 14a supported by an intermediate rotating shaft 15, and is supported so as to be swingable about the intermediate rotating shaft 15. A feeding roller means 11 is provided at a distal end portion 14b of the elevating arm member 14. It is bearing. The feeding roller means 11 may be constituted by an endless belt spanned between a pair of front and rear pulleys, but the illustrated one shows a case where it is constituted by a roller member, which is hereinafter referred to as a pickup roller 11.

  The intermediate rotating shaft 15 is rotatably supported by the apparatus frame, and a driving rotational force is transmitted from a driving rotating shaft 18 to be described later via an intermediate gear 16 as shown in FIG. A sheet feeding roller 12 is supported on the intermediate rotation shaft 15 via a one-way rotation clutch 12a, and rotates in the clockwise direction (sheet feeding direction) in FIG. The paper feed roller 12 is pressed against the separating member 32 and separates the original sheets one by one and feeds them downstream. The rotation of the intermediate rotation shaft 15 is transmitted to the pickup roller 11 by a transmission means such as a transmission belt 17 in the paper feeding direction (clockwise in FIG. 3). On the other hand, a base end portion 14a of an elevating arm member 14 that supports the pickup roller 11 is loosely supported by the intermediate rotating shaft 15, and friction transmission means (shown as a spring clutch 15a; The same).

  Accordingly, the rotation of the intermediate rotation shaft 15 is transmitted to the feed roller 12 and the pickup roller 11 in one direction (feeding direction), and the rotation in both forward and reverse directions is transmitted to the lifting arm member 14. At this time, after the lifting / lowering arm member 14 receives the rotation of the intermediate rotation shaft 15 via the spring clutch 15a and comes into contact with the seat at the operating position and after being locked to the stopper member (not shown) at the retracted position. The spring clutch 15a rolls “slide”.

  Accordingly, the sheet feeding motor M1 is connected to the intermediate rotating shaft 15 as follows. As shown in FIG. 3, a drive rotary shaft 18 is supported by a device frame (not shown) at a position spaced from the intermediate rotary shaft 15, and a drive gear 19 is supported on the drive rotary shaft 18. Further, a rotary arm member 20 is pivotally supported on the drive rotary shaft 18 via a shift means (the illustrated one is a spring clutch 18a; the same applies hereinafter). The transmission gear 21a and the second transmission gear 21b are axially supported. As shown in FIG. 5A, the illustrated rotating arm member 20 is constituted by a bifurcated lever, and a first transmission gear 21a is supported on one side and a second transmission gear 21b is supported on the other side. The first and second transmission gears 21 a and 21 b are engaged with the drive gear 19, respectively, and are configured as a satellite gear mechanism that rolls along the outer periphery of the drive gear 19.

  The first and second transmission gears 21a and 21b mesh with the intermediate gear 16 described above (see FIGS. 5A and 5B). Therefore, if the drive rotary shaft 18 is rotated forward and backward, the rotary arm member 20 is swung in the clockwise direction and the counterclockwise direction in FIG. 5 by the action of the spring clutch 18a, and the first transmission gear 21a and the first transmission gear 21a selectively 2 The transmission gear 21b meshes. Therefore, the forward and reverse rotations are transmitted from the first and second transmission gears 21a and 21b to the intermediate gear 16 described above. A paper feed motor M <b> 1 is connected to the drive rotating shaft 18 via a transmission belt 23. The spring clutch 18a is disposed between the drive rotary shaft 18 and the drive gear 19, but it may be disposed between the drive rotary shaft 18 and the rotating arm member 20. Further, a rotation shaft 25 of the registration roller 13 is connected to the paper feed motor M1 via a one-way rotation clutch 26 via a gear train 24. The one-way rotation clutch 26 has a relationship of transmitting the driving force in the opposite direction to the one-way rotation clutch 12a of the previous paper feed roller 12. That is, the feed roller 12 and the pickup roller 11 are driven and rotated by the forward rotation of the drive motor M1 (the clockwise rotation is illustrated), and the registration roller 13 is driven and rotated by the reverse rotation (counterclockwise rotation). ing.

  With the above configuration, only the sheet feeding roller 12 and the pickup roller 11 are driven and rotated in the sheet feeding direction by the forward rotation of the sheet feeding motor M1, and only the pickup roller 11 is driven and rotated in the sheet feeding direction by the reverse rotation. At the same time, the lifting arm member 14 that supports the pickup roller 11 is shifted from the retracted position to the operating position by the forward rotation of the motor M1, and is shifted from the operating position to the retracted position by the reverse rotation of the paper feed motor M1. Therefore, a restricting means 27 for restricting the movement of the above-described rotating arm member 20 is arranged as will be described later in order to keep the pickup roller 11 in an operating state even when the sheet feeding motor M1 rotates in the reverse direction.

  The drive of the carry-in roller 41, the carry-out roller 42, and the paper discharge roller 43 will be described below. As shown in FIG. 4, the conveyance motor M2 is transmitted to the rotary shaft 46 through the transmission belt V1, and is discharged from the rotary shaft 46. The drive shaft 43a of the paper roller 43 is connected by a transmission belt V2. Further, the drive is transmitted from the rotary shaft 46 to the drive shaft 41a of the carry-in roller 41 and the drive shaft 42a of the carry-out roller 42 via the transmission belt V3. The transmission belt V3 is provided with a transmission pulley 46a, and a one-way rotation clutch (not shown) is built in between the transmission pulley 46a and the rotation shaft 46, and only in one direction of forward and reverse rotation of the rotation shaft 46. Is transmitted to the drive shaft 41a and the drive shaft 42a. Accordingly, the forward / reverse rotation of the transport motor M2 is transmitted to the paper discharge roller 43, and only its one-way rotation is transmitted to the carry-in roller 41 and the carry-out roller 42.

  Therefore, the rotation of the rotary shaft 46 is transmitted to the control shaft 48 via the gear train 47, and the control shaft 48 is provided with a regulating means 27 including a first lever 27a and a second lever 27b. A first lever 27a is loosely supported by the control shaft 48 connected to the transport motor M2. A slip clutch 48a is provided between the control shaft 48 and the first lever 27a so as to swing the first lever 27a within a predetermined angle range. A second lever 27b is engaged with the first lever 27a as shown in FIG. First, the second lever 27b is pivotally supported so as to be swingable between the state shown in FIG. 5A in which the rotation of the rotating arm member 20 is restricted and the state shown in FIG. ing.

  The second lever 27b biases the first lever 27a to the stopper 49b by the biasing spring 49a. At the same time, the second lever 27b stops at the stopper 49c when the first lever 27a is rotated by the action of the sliding clutch 48a. It has become. Accordingly, when the control shaft 48 rotates (clockwise in FIG. 5), the first lever 27a swings from the state of FIG. 5 (a) to the state of FIG. 6 (b), and the second lever 27b rotates in conjunction with this. The movement of the arm member 20 is restricted to a non-transmission state where the first and second transmission gears 21 a and 21 b do not mesh with the intermediate gear 16. After this movement restriction, the rotation of the control shaft 48 slides between the first lever 27a by the sliding clutch 48a.

An operation for feeding the sheet will be described with reference to FIGS. 5A to 7B.
"Initial state"
5A, the pickup roller 11 is held in the retracted position, and the rotating arm member 20 is held in the position where the second transmission gear 21b is engaged with the intermediate gear 16. Yes. The pickup roller 11 is held at the retracted position by the load of the drive system. The original sheet can be set on the paper feed stacker 10 with the pickup roller 11 in the retracted position.

"When feeding is started"
As shown in FIG. 5B, an original sheet is set, and the paper feed motor M1 is activated by a paper feed start signal to rotate the drive rotary shaft 18 clockwise. With this rotation, the drive gear 19 rotates through the spring clutch 18a. As the drive gear 19 rotates, the rotating arm member 20 rotates clockwise from the position shown in FIG. 5A to the state shown in FIG. Then, the second transmission gear 21b meshed with the intermediate gear 16 is released, and the first transmission gear 21a is meshed. With this connection, the intermediate gear 16 rotates clockwise. Then, the intermediate rotation shaft 15 rotates in the clockwise direction, and the lifting arm member 14 receives the frictional rotational force from the spring clutch 15a and swings in the clockwise direction. The pickup roller 11 is moved from the retracted position to the operating position in contact with the document sheet by the swinging of the lifting arm member 14. In this operating position, the spring clutch 15a is set on the loose side so as to slide between the lift arm member 14 and the spring clutch 15a. As a result, the pickup roller 11 contacts the original sheet with a predetermined pressing force and feeds it downstream.

"Registration correction"
When the pickup roller 11 feeds the original sheet on the paper feed stacker 10 by the clockwise rotation of the paper feed motor M 1, the paper is separated one by one by the paper feed roller 12 and reaches the registration roller 13. At this time, the registration roller 13 is stopped and the leading edge of the document sheet is abutted to correct the skew. After this skew correction, the paper feed motor M1 is stopped. After stopping the paper feed motor M1, the transport motor M2 is driven in the forward direction. Then, the control shaft 48 rotates and the first lever 27a is rotated clockwise through the spring clutch 48a. By the rotation of the first lever 27a, the second lever 27b rotates counterclockwise from the state shown in FIG. 5B to the position of the stopper 49c against the biasing spring 49a to be in the state shown in FIG. 6A. . During the forward rotation of the transport motor M2, the spring clutch 15a is slid with the set torque at the position where it is in contact with the stopper 49c, and the second lever 27b is pressed and held at the stopper position.

“Paper sheet feeding”
After the skew correction is completed and the second lever 27b is pressed and held at the position of the stopper 49c, the paper feed motor M1 is reversely rotated. The registration roller 13 is rotated to feed the original sheet toward the reading platen (second platen) 30. At the same time, the drive rotation shaft 18 rotates counterclockwise by the reverse rotation of the paper feed motor M1, and the drive gear 19 and the rotating arm member 20 are counterclockwise from the state of FIG. 6A to the state of FIG. 6B. To turn. The rotation of the rotating arm member 20 moves the first transmission gear 21a so that the second transmission gear 21b and the intermediate gear 16 are connected to each other, but the second lever 27b pressed and held at the stopper position is moved to the second lever 27b. The movement of the first transmission gear 21a is restricted, and the rotation arm member 20 is prevented from rotating, and the connection with the intermediate gear 16 remains disconnected as shown in FIG. 6B. At this time, the pick-up roller 11 is not driven and the original sheet is fed by the registration roller 13 while being stationary on the original sheet, and is transferred to the carry-in roller 41 to read the original. For this reason, there is no impact due to the swinging motion of the pickup roller 11 at the time of paper feeding, and satisfactory document reading is possible.

"Operation after sheet feeding"
When all the original sheets set on the paper feed stacker 10 are fed and the original reading is completed, the transport motor M2 is stopped. Thereafter, the transport motor M2 is reversely rotated so that the rotating arm member 20 is rotated counterclockwise from the position of FIG. 6B to return to the initial position regulated by the stopper 49b. The second lever 27b also returns to the initial position following the rotation of the rotary arm member 20 by the biasing spring 49a as the rotary arm member 20 rotates. Subsequently, as shown in FIG. 7B, when the second lever 27b returns to the initial position, the paper feed motor M1 is reversely rotated, and the rotating arm member 20 is also rotated as the drive gear 19 rotates. From the position to the position of FIG. 7B in the counterclockwise direction. As the rotary arm member 20 rotates, the second transmission gear 21b and the intermediate gear 16 are connected to drive the intermediate gear 16, the spring clutch 15a is locked, and the pickup roller 11 swings up from the stacker surface. Returning to the initial retracted position, the paper feeding operation is completed.

  Hereinafter, with respect to the document feeding apparatus A shown in FIG. 1, the operation of feeding a document sheet from the sheet feed stacker 10 to the reading platen (second platen) 30 is performed when reading one side image of the document sheet and when reading both side images. explain.

"Single-sided image reading operation"
Referring to the flowchart of FIG. 9, first, when the apparatus is activated, the pickup roller 11 is located at the retracted position above the paper feed stacker 10. Therefore, the original sheet is set and the paper feeding is started (ST100). First, when the paper feed motor M1 is rotated forward (ST101), the drive rotary shaft 18 is rotated, and the rotation is transmitted to the drive gear 19 and the rotary arm member 20 via the spring clutch 18a. Therefore, the rotating arm member 20 rotates clockwise from the state of FIG. 5A to the state of FIG. With this rotation, the first transmission gear 21 a meshes with the intermediate gear 16, and the rotation of the drive rotary shaft 18 is transmitted to the intermediate rotary shaft 15. The rotation of the intermediate rotation shaft 15 is transmitted to the paper feed roller 12 via the one-way rotation clutch 12a and rotates in the clockwise direction. At the same time, the pickup roller 11 is rotated clockwise through the transmission belt 17.

  On the other hand, the rotation of the intermediate rotating shaft 15 applies a clockwise rotational force to the base end portion 14a of the elevating arm member 14 via the spring clutch 15a as shown in FIG. The pickup roller 11 attached to the lifting arm member 14 is moved from the retracted position to the operating position where it engages with the original sheet on the paper feed stacker 10 (ST102). At this operating position, the pickup roller 11 feeds the original sheet downstream, and simultaneously feeds it to the paper feed roller 12 that rotates. The original sheet is separated into a single sheet between the paper feed roller 12 and the separating member 32 and sent downstream (ST103). In this process, since the spring clutch 15a is set to the loose side by rotation in the paper feeding direction, it “slides” between the lift arm member 14 with a predetermined pressing force applied to the pickup roller 11.

  The original sheet separated by the paper feed roller 12 is sent to the resist roller 13 in a stopped state and abutted on the leading edge. The skew is corrected (ST104) by the curvature of the leading edge of the original sheet. In other words, the registration roller 13 is drivingly connected to the sheet feeding motor M1 via the one-way rotation clutch 26. At the time of sheet feeding, the registration roller 13 is not driven and the rotation in the sheet conveyance direction is locked because the clutch 26 is OFF. It is possible to reliably hit the sheet.

  After the estimated time for completing the skew correction, the paper feed motor M1 is stopped (ST105). Next, the transport motor M2 is driven in reverse (ST106). The rotation of the transport motor M2 is transmitted to the control shaft 46, and the first lever 27a swings to the state shown in FIG. 6A via the spring clutch 48a functioning as a torque limiter, and engages with the second lever 27a. The lever 27b also contacts the stopper 49c against the biasing spring 49a (ST107). In this state, the spring clutch 48a continues to slide. Next, the paper feed motor M1 is reversely rotated (ST108). By this rotation, the one-way rotation clutch 26 for driving transmission to the registration roller 13 is turned on, and the registration roller 13 is rotationally driven in the sheet conveying direction.

  The above-described rotating arm member 20 is rotated counterclockwise as the drive gear 19 is rotated by the reverse rotation of the sheet feeding motor M1, but its movement is restricted by the second lever 27b at a predetermined position as shown in FIG. As shown in b), both the first transmission gear 21a and the second transmission gear 21b are in a non-transmission state in which the connection with the intermediate gear 16 remains disconnected (ST109). Accordingly, the document sheet is conveyed by the registration roller 13 while the pick-up roller 11 remains stationary on the document sheet (ST110). The original sheet conveyed by the registration roller 13 is transferred to the downstream carry-in roller 41 and conveyed through the conveyance path 40 (ST111), and image reading is performed while conveying the original sheet at a predetermined speed onto the second platen 30. (ST112). The document sheet after reading is conveyed toward the paper discharge stacker 31 by the downstream carry-out roller 42 (ST116).

  It is determined whether there is a next original sheet in the paper feed stacker 10 (ST117). If there is a next original, the process returns to step 103. That is, while the transport motor M2 is driven in the normal direction, the paper feed motor M1 is driven in the normal direction to shift to the paper feeding operation (ST103). By the forward rotation of the paper feed motor M1, the turning arm member 20 turns clockwise as the drive gear 19 rotates, and is transmitted from the drive gear 19 to the intermediate gear 16 via the first transmission gear 21a. 12 and the pickup roller 11 are rotationally driven in the paper feeding direction. At this time, the pickup roller 11 is in a free state where the pickup roller 11 is stationary on the original sheet, and the pickup roller 11 can take in the sheet without swinging the pickup roller 11 during paper feeding. Document reading is possible.

  On the other hand, when all the set originals are fed and the original reading is completed, the transport motor M2 stops (ST118), and the original feeder A is returned to the initial standby state. First, the transport motor M2 is rotated in the reverse direction (ST119), and the rotary arm member 20 is rotated counterclockwise from the position shown in FIG. 6B as shown in FIG. (ST120). Similarly, the second lever 27b is returned to the initial retracted position by the urging spring 49a by the rotation of the rotating arm member 20. Subsequently, as shown in FIG. 7B, when the second lever 27b returns to the retracted position, the paper feed motor M1 is reversely rotated (ST121), and the rotating arm member 20 is also rotated as the drive gear 19 rotates. It rotates counterclockwise from the position (a) to the position shown in FIG. 7 (b). As the rotary arm member 20 rotates, the second transmission gear 21b and the intermediate gear 16 are connected (ST122), the intermediate gear 16 is driven, the spring clutch 15a is locked, and the pickup roller 11 swings from the stacker surface. Ascend (ST123) and return to the initial retracted position to complete the paper feeding operation (ST126).

"Double-sided image reading operation"
The double-sided operation flow for reading the front and back sides of the original shown in FIG. 10 is the same as the single-sided operation flow until the original is set on the paper feed stacker 10, the paper feed is started, the surface of the first sheet is read and discharged. . In the double-sided operation, in order to read the back side of the sheet, after reading the front side, the sheet is switched back from the rear end of the sheet and conveyed to the reading platen 30 through the registration roller 13. Further, in order to align the page order on the paper discharge stacker 31, after reading the back side, the sheet is switched back from the rear end of the sheet, and discharged to the paper discharge stacker 31 through the registration roller 13 without performing a reading operation. In the following, a detailed description will be given after the completion of the surface reading of the first sheet.

  A document is set on the paper feed stacker 10, and feeding is started to complete reading of the first surface of the first sheet. A sheet is conveyed to the paper discharge stacker 31 side by the carry-out roller 42 and is at the exit of the conveyance path 40. After the trailing edge of the sheet passes through the path switching guide 44, the conveyance motor M2 stops for a predetermined time and reverses. By the reverse rotation of the conveyance motor M2, the sheet is switched back from the rear end, and the sheet is switched back along the circulation path 45 to the registration roller 13 using the back surface of the path switching guide 44 as a path guide. Further, by the reverse rotation of the transport motor M2, the rotating arm member 20 rotates counterclockwise and returns to the initial retracted position regulated by the stopper 49b. The second lever 27b also returns to the initial retracted position following the rotation of the rotary arm member 20 by the biasing spring 49a as the rotary arm member 20 rotates.

  At this time, the sheet feeding motor M1 that drives the registration roller 13 is stopped, and the trailing edge of the sheet conveyed by the switchback loops against the registration roller 13 and absorbs sheet slack by a curved guide provided in front of the registration roller 13. To correct the skew. After the skew correction, the conveyance motor M2 is stopped, the sheet feeding motor M1 is driven in reverse to drive the registration roller 13, and the sheet is conveyed from the rear end to the carry-in roller 41. Here, the rotation arm member 20 rotates counterclockwise as the drive gear 19 rotates due to the reverse rotation of the paper feed motor M1, and the second transmission gear 21b and the intermediate gear 16 are connected to bring the spring clutch 15a into the locked state. The pickup roller 11 swings up from the stacker surface and returns to the retracted position.

  The sheet conveyed from the registration roller 13 is transferred to the carry-in roller 41, and reading of the back surface of the sheet is performed while conveying the sheet on the second platen 30 serving as a reading unit. The sheet feeding motor M1 stops when the trailing edge of the sheet passes through the carry-in roller 41. After the reading of the back side of the sheet is completed, the sheet is further conveyed to the exit of the conveyance path 40 by the downstream carry-out roller 42 and guided toward the paper discharge stacker 31 by the path switching guide 44 at the exit.

  When the sheet exits the path switching guide 44, the conveyance motor M2 stops once, and then the conveyance motor M2 is driven in reverse to complete the reading of both sides of the sheet again to align the page order on the discharge stacker 31. The color is reversed and conveyed to a circulation path 45 that goes to the reading platen 30 through the registration roller 13. Further, the rotation arm member 20 is rotated counterclockwise by the reverse rotation of the transport motor M2, and returns to the initial retracted position regulated by the stopper 49b. Further, the second lever 27b also returns to the initial retracted position following the rotation of the rotating arm member 20 by the biasing spring 49a as the rotating arm member 20 rotates. Here, “color reversal conveyance” refers to conveyance in which an original image is passed through the reading platen 30 without being read (the same applies hereinafter).

  The leading edge of the sheet that has been reversely conveyed is brought into contact with the registration roller 13 and the skew is corrected by the curved guide before the registration roller 13, and then the conveyance motor M2 is stopped once. After the conveyance motor M2 is stopped, the sheet feeding motor M1 is driven in reverse to drive the registration roller 13 and convey the sheet to the carry-in roller 41. Immediately after the paper feed motor M1 is reversely rotated, the conveyance motor M2 is driven forward to deliver the sheet from the registration roller 13 to the carry-in roller 41, and is conveyed downstream by the carry-in roller 41 via the reading platen 30. At this time, the reading operation is not performed because both-side reading has already been completed. Further, the rotation arm member 20 is rotated clockwise by the forward drive of the transport motor M2, and the second lever 27b is held at the stopper 49c position against the biasing spring 49a. The sheet is delivered to the carry-in roller 41, and the sheet feeding motor M1 is stopped after the trailing edge of the sheet has passed through the registration roller 13.

  If there is a next sheet to be read in the paper feed stacker 10, the paper feed motor M1 is driven to rotate forward while the color reversal transport sheet passes through the reading platen 30 and is discharged to the paper discharge stacker 31 by the carry-out roller 42. Move to operation. At this time, the pickup roller 11 swings up and returns to the retracted position during registration conveyance on the back side of the sheet that is reversed in parallel, and the pickup roller 11 returns to the sheet surface by the normal rotation of the sheet feeding motor M1. Swing down. At this time, the reading platen 30 does not perform a reading operation, so there is no problem.

  When all the documents set on the sheet feed stacker 10 are fed and the document reading is completed, the transport motor M2 is stopped, and then the document feeder A is returned to the initial standby state. First, the transport motor M2 is reversely rotated to rotate the rotating arm member 20 counterclockwise to return to the initial retracted position regulated by the stopper 49b. The second lever 27b also returns to the initial retracted position following the rotation of the rotary arm member 20 by the biasing spring 49a as the rotary arm member 20 rotates. Subsequently, when the second lever 27b returns to the retracted position, the sheet feeding motor M1 rotates in the reverse direction, and the rotating arm member 20 moves from the position of FIG. It rotates counterclockwise to the position. As the rotary arm member 20 rotates, the second transmission gear 21b and the intermediate gear 16 are connected to drive the intermediate gear 16, the spring clutch 15a is locked, and the pickup roller 11 swings up from the stacker surface. Returning to the initial retracted position, the paper feeding operation is completed.

1 is an overall configuration diagram of a document feeding device incorporating a paper feeding device according to the present invention. FIG. The principal part expansion explanatory drawing of the apparatus of FIG. FIG. 2 is an explanatory diagram of a paper feed unit driving mechanism in the apparatus of FIG. 1. FIG. 3 is an explanatory diagram of a paper discharge unit driving mechanism in the apparatus of FIG. 1. It is operation | movement explanatory drawing of the drawing roller means in the apparatus of FIG. 1, (a) is a state explanatory view at the time of apparatus starting, (b) is explanatory drawing of a drive initial state. 2A and 2B are operation explanatory views of a feeding roller unit in the apparatus of FIG. 1, in which FIG. 1A is an explanatory diagram of a sheet feeding state, and FIG. FIGS. 2A and 2B are operation explanatory views of a feeding roller unit in the apparatus of FIG. 1, in which FIG. 1A is an explanatory view of a state that returns to an initial state after completion of sheet feeding, and FIG. Illustration. Structure explanatory drawing of the spring clutch of FIG. Flowchart at the time of single-sided image reading in the document feeder Flowchart when reading double-sided image in document feeder

Explanation of symbols

A Document feeder B Scanner device 10 Paper feed stacker 11 Pickup roller (feeding roller means)
12 Paper feed roller (paper feed rotation means)
13 Registration roller 14 Lifting arm member 15 Intermediate rotating shaft 16 Intermediate gear 15a Spring clutch (friction transmission means)
18 Drive rotary shaft 19 Drive gear 20 Rotating arm member 21a First transmission gear 21b Second transmission gear 27 Restricting means 27a First lever 27b Second lever 30 Reading platen 48 Control shaft

Claims (10)

A placement guide for supporting the sheet;
A feeding roller means for feeding the sheet on the placement guide to the downstream side;
An elevating arm member that swingably supports the feeding roller means between an operating position for engaging the sheet on the placement guide and a retracted position separated from the sheet;
A paper feeding device provided with a driving means for rotationally driving the feeding roller means,
A drive rotary shaft having a drive gear coupled to the drive means;
An intermediate rotation shaft having an intermediate gear disposed at a distance from the drive rotation shaft;
A first and a second transmission gear attached to the drive rotation shaft so as to be able to swing around the outer periphery of the drive gear,
The lift arm member is pivotally supported on the intermediate rotation shaft via a friction transmission means, and
The feeding roller means is driven and transmitted from the intermediate gear by transmission means,
The first transmission gear meshes with the intermediate gear by one-way rotation of the drive rotation shaft to swing and rotate the lifting arm member in a predetermined direction, and the second rotation by reverse rotation of the drive rotation shaft. A paper feeding device characterized in that a transmission gear meshes with the intermediate gear to swing and rotate the lifting arm member in the opposite direction. The drive rotary shaft is provided with a pivot arm member that can swing around the drive rotary shaft, and a shift means that controls the pivot arm member.
The first and second transmission gears are supported by the rotating arm member,
The paper feeding device according to claim 1, wherein the first and second transmission gears are selectively meshed with the intermediate gear by the shift means. The shift means is composed of a spring clutch or other friction transmission means that is disposed between the drive rotation shaft and the rotation arm member and transmits the rotation of the drive rotation shaft to the rotation arm member. The paper feeding device according to claim 2. The said shift means is further provided with the control means which controls a motion of the said rotation arm member in the non-transmission state which does not mesh | engage the said 1st 2nd transmission gear with the said intermediate gear. The paper feeding device described in 1. The placement guide is composed of a sheet stacker that stacks and stores sheets.
The feeding roller means is supported by the elevating arm member so as to be swingable between an operating position and a retracted position on the paper feed stacker,
A sheet feed roller for separating and feeding sheets from the sheet feed stacker one by one is connected to the intermediate rotation shaft via a one-way rotation clutch.
5. The registration roller according to claim 1, wherein a registration roller for carrying the sheet from the sheet feeding roller downstream is connected to the driving rotation shaft via a one-way rotation clutch. Paper feeder. A paper feed stacker on which a document sheet is placed;
A feed roller means for sequentially feeding the original sheets from the paper feed stacker;
An elevating arm member that swingably supports the feeding roller means between an operating position for engaging the document sheet on the sheet feeding stacker and a retracted position separated from the document sheet;
A paper feed roller for separating and feeding original sheets from the feeding roller one by one;
A registration roller that takes over and conveys the original sheet from the paper feed roller;
A reading platen disposed downstream of the registration roller;
A document feeding device including a reading roller disposed between the registration roller and the reading platen and feeding a document sheet to the reading platen;
A drive rotary shaft having drive means;
A drive gear attached to the drive rotation shaft;
An intermediate rotation shaft having an intermediate gear disposed at a distance from the drive rotation shaft;
A first and a second transmission gear attached to the drive rotation shaft so as to be able to swing around the outer periphery of the drive gear,
The lift arm member is pivotally supported on the intermediate rotation shaft via a friction transmission means, and
The feeding roller means is driven and transmitted from the intermediate gear by transmission means,
The first transmission gear meshes with the intermediate gear by one-way rotation of the drive rotation shaft to swing and rotate the lifting arm member in a predetermined direction, and the second rotation by reverse rotation of the drive rotation shaft. A document feeding device, wherein a transmission gear meshes with the intermediate gear to swing and rotate the lifting arm member in the opposite direction. The paper feed roller is connected to the intermediate rotation shaft via a one-way rotation clutch,
The drive means connected to the drive rotary shaft is composed of a drive motor capable of forward and reverse rotation,
The registration roller is connected to the drive motor via a one-way rotation clutch,
The document feeder according to claim 6, wherein the feeding roller and the registration roller are driven and transmitted in a reciprocal manner by the rotation of the driving motor. A rotating arm member provided with the first and second transmission gears is pivotally connected to the drive rotation shaft via a friction transmission means,
The rotating arm member includes a restricting means for restricting movement of the first and second transmission gears to a non-transmission state in which the first and second transmission gears do not mesh with the intermediate gear,
The document feeder according to claim 7, wherein the restricting unit is connected to a drive motor that drives the reading roller. A paper feed stacker for placing sheets;
A feeding roller means disposed above the paper feed stacker;
A sheet feeding rotation means for separating and feeding the sheets from the feeding roller means one by one;
A registration roller disposed on the downstream side of the sheet feeding rotation means, and for correcting the registration of the leading edge of the sheet;
An elevating arm member that supports the feeding roller means so as to be swingable between an operating position that engages with a sheet on the paper feed stacker and a retracted position that is spaced upward;
A carry-in roller for conveying the sheet from the registration roller to a predetermined reading position;
A carry-out roller for carrying out the sheet from the reading position;
A first driving motor for driving and rotating the feeding roller means, the paper feed rotating means, and the registration roller;
A second drive motor for driving and rotating the carry-in roller and the carry-out roller;
The lifting and lowering arm member is connected and supported by a uniaxial frictional transmission means at the base end portion thereof to the rotation support shaft,
A first and second transmission gear that transmits forward and reverse rotations to the rotation support shaft connected to the first drive motor, and a passive unit provided on the rotation support shaft with the first and second transmission gears. Shift means for selectively engaging the gear and transmitting the drive;
The shift means is configured to switch the drive transmission by the rotation of the second drive motor.
The document feeding device, wherein the feeding roller means is drivingly connected to the rotating support shaft by transmission means. The friction transmission means comprises a spring clutch,
The first and second transmission gears are supported by a rotating arm member so as to roll on the outer periphery of a drive gear connected to the first drive motor,
The shift means is configured to selectively mesh the first and second transmission gears with the passive gear in the rotation direction of the first drive motor. The document feeder according to claim 9.

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